The present invention relates to a first record medium on which original data (there are two cases: when the term “original data” is used in the specification an original data which becomes record target to the record medium and an original data which becomes a presentation target from the record medium) is recorded, and a second record medium, which is distinguishable from the first record medium, on which data copied from the first record medium is recorded. This invention also relates to a record medium capable of preventing an unauthorized copy of the original data, a record medium manufacturing device, a computer readable record medium on which a program is recorded, and a data presentation device which presents the data on the record medium.
Various record media to store the digital data of the multimedia data have been developed in recent years. If data is copied from the digital record medium, a record medium on which the same data as the original data is copied is created. It is important to prevent an unauthorized copy to protect a copyright, and in addition, to develop a technology and a market which uses the medium which contains contents from the copyright holder.
For example, conventionally, in some digital record media such as a DAT (Digital Audio Tape) and MD (Mini Disc), a technology which can perform only once (first generation) digital copy is provided, in addition to a general medium in which copying is completely permitted (copy freely).
These technologies are called CGMS (Copy Generation Management System) and SCMS (Serial Copy Management System), and have a mechanism such that prevents copying (second generation) from the medium manufactured by copying from the medium to which only the first generation copy is permitted. As a result, an unauthorized copy cannot be manufactured.
In CGMS and SCMS, information as to whether it is a copied medium (Whether a copy of a next generation can be performed or not?) is shown by flag information in two bits.
However, in such CGMS and SCMS, it is comparatively easy to falsify this on the transmission line when the flag information is transmitted with the main body of contents. Therefore, there is a problem that an unauthorized copy may be performed by the falsification of the flag information. The medium to which it is copied without authorization is generally called a piracy edition, which can circulate.